Aquarium plants and animals need to be kept within specific temperature ranges. If your aquarium is running too hot, it may be time to look at a chiller to help cool things down.
If You Can't Take the Heat, Get A Chiller!
These large pieces of equipment seem high-tech and confusing, but they are really just special air-conditioner-like appliances that keep your tank from heating up too much.
What Could Cause a Tank to Heat Up?
The tank is kept in a room full of potentially warm equipment, like a TV, high-power lamps, oven, whatever.
Is your tank against 2 walls, and is it not getting enough circulation around it?
Is your light hood vented (especially if you have halides) so that heat can escape?
Are your heater(s) the right wattage and are they working correctly?
Do you have a lot of power heads or pumps that might be giving off extra heat?
If any of these reasons could be the heat culprit, we suggest moving the aquarium to a cooler room, like a basement, or away from walls so air can circulate. Recommend checking the heaters or trying a different pump, and venting the hood so that heat can escape. If none of these things seem to work, then we go with a Chiller!
Choosing the Correct Chiller
Total gallons in aquarium (including sump)
The number of degrees you want the temperature to drop.
The total wattage of all other devices that might contribute to the heat.
The placement of the tank (direct sunlight?).
The temperature of the room that the aquarium is in.
The amount of live rock (which is a natural insulator and holds heat.)
Ventilation for the chiller. (away from walls, etc.)
Flow rate. Flow rate is very important. You must choose the pump you need to use with your chiller very carefully. For example, a RIO 800 pump can put out 211 gph, but this is at zero head (which means the water does not have to travel up through any tubing), at 4 feet of head the gph drops down to 60. You must take into consideration that the flow rates of pumps will greatly decrease as the head increases. Determine the required flow rate for the chiller you are considering. For example, say one chiller requires a flow rate of 2-3 gallons per minute. This means that the pump should push the water into and out of the chiller and back into the tank at 120-180 gph. You should be able to fill a one gallon jug 2-3 times in a minute. If you don't meet the proper flow rate, the chiller won't function properly.
Most Chillers have this sort of information within their packaging, so it is much easier to decide on one by their information, rather than going through #s 1-8 and trying to figure out the right chiller. A Chiller will usually give two stats, the # of gallons this chiller will affect with a 10 degree temp change, and the # of gallons it will affect with a 30 degree temp change. As far as Chiller designs and functions, many sit beside the sump area and pump water through the unit and this is how it is cooled. Other types, called "drop-ins" have a coil that you put in your sump that will cool the water as it passes through the sump system. Most chillers have the ability to read the temperature within a tank. Some newer designs even have a built in heating control, which turns heaters off and on as needed.